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From Paulo Ricardo Motta Gomes <paulo.mo...@chaordicsystems.com>
Subject Re: Question: ConsistencyLevel.ONE with multiple datacenters
Date Thu, 06 Feb 2014 14:47:30 GMT
Cool. I actually changed the consistency level to LOCAL_ONE and things
worked as expected.

Cheers!


On Thu, Feb 6, 2014 at 11:31 AM, Chris Burroughs
<chris.burroughs@gmail.com>wrote:

> I think the scenario you outlined is correct.  The DES handles multiple
> DCs poorly and the LOCAL_ONE hammer is the best bet.
>
>
> On 01/31/2014 12:40 PM, Paulo Ricardo Motta Gomes wrote:
>
>> Hey,
>>
>> When adding a new data center to our production C* datacenter using the
>> procedure described in [1], some of our application requests were
>> returning
>> null/empty values. Rebuild was not complete in the new datacenter, so my
>> guess is that some requests were being directed to the brand new
>> datacenter
>> which still didn't have the data.
>>
>> Our Hector client was connected only to the original nodes, with
>> autoDiscoverHosts=false and we use ConsistencyLevel.ONE for reads. The
>> keyspace schema was already configured to use both data centers.
>>
>> My question is: is it possible that the dynamic snitch is choosing the
>> nodes in the new (empty) datacenter when CL=ONE? In this case, it's
>> mandatory to use CL=LOCAL_ONE during bootstrap/rebuild of a new
>> datacenter,
>> otherwise empty data might be returned, correct?
>>
>> Cheers,
>>
>> [1]
>> http://www.datastax.com/documentation/cassandra/1.2/
>> webhelp/cassandra/operations/ops_add_dc_to_cluster_t.html
>>
>>
>


-- 
*Paulo Motta*

Chaordic | *Platform*
*www.chaordic.com.br <http://www.chaordic.com.br/>*
+55 48 3232.3200
+55 83 9690-1314

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